This summer was one of the warmest and wettest on record, based on preliminary data. The statewide average temperature for summer (June–August) in Illinois was 76.4 degrees, 2.7 degrees above normal and the seventh warmest summer on record, according to the Illinois State Water Survey.
The average rainfall for summer in Illinois was 16.7 inches, 5.2 inches above normal, ranking as the sixth wettest summer on record. Statewide records extend back to 1895. The heaviest rains occurred in western and northern Illinois.
Meanwhile, August rainfall was close to normal with a statewide average of 3.4 inches, just 0.3 inches below normal. However, significant areas in east-central and southern Illinois received less than half that amount. For example, Champaign reported 1.64 inches for the month.